Protective helmets are used in a variety of activities, such as in the military and in law enforcement. These helmets often comprise a rigidly formed shell for protection and a support system for supporting the helmet in relation to the user's head. The support system typically comprises straps that extend from the rim of the shell of the helmet to wrap around a portion of the user's head or neck, usually around the chin or the nape of the neck.
For some helmets, different attachments are desired or necessary based on the activity to be performed. One such attachment includes a night vision goggle unit. During activities or operations under darkened conditions, a user may wear the night vision goggle unit to facilitate vision in low levels of light. The night vision goggle unit attaches to the front of the helmet in the region approximate to the location of the user's forehead. Ideally the center of mass for such a system would be directly over the top of a user's head; such that there is no offset to the weight, as an offset weight causes a tendency to rotate that must be counteracted by the user's neck muscles to maintain equilibrium. The night vision goggle unit is quite heavy (often 2 pounds or more), and users may have to wear the system for hours at a time, typically causing neck strain and fatigue. Because the additional weight of the night vision goggle unit may cause the center of mass of the helmet to be shifted forward, causing the helmet to tilt down over the user's face, the shift forces the user to activate neck muscles to prevent the tilt.
Due to the weight of the night vision goggle unit, the support straps of the helmet may often be inadequate to hold the helmet with the attached night vision goggles in place upon a user's head such that the rim of the helmet is parallel to the ground. Furthermore, the center of mass offset typically allows a relatively heavy helmet and night vision goggle attachment to swing about on a user's head with unintentionally high degrees of freedom. This means the helmet may have mobility free of the user, and thus may not remain as securely in place as desired.
Therefore, for the purpose of balancing the weight of the night vision goggle unit such that a helmet may remain stable upon a user's head, current products addressing the issue utilize a counterweight system that uses mechanical means of attachment to the back of a helmet, such that the counterweight hangs from the bottom rim of the helmet based on the geometry of the counterweight. Current products lack adjustability of the placement of a counterweight, such that the product is not capable of accommodating various preferences or parameters of different users. Moreover, current products must be removed to maintain balance if the night vision goggle unit is removed, leaving the necessity to store the current product when not in use. Contributing to this problem, military and law enforcement personnel typically carry heavy and cumbersome equipment, such that there is a strong benefit associated with multi-purpose equipment capable of various tasks.
Thus a need exists for a counterweight system that will move the center of mass of a helmet with front-loaded attachments to an ideal position, acting through the center of the user's neck, and thus preventing the tilt caused by the weight of the night vision goggles. This change of the effective locus of the center of mass reduces or removes any neck strain of the user that is required to hold the helmet in place, as the helmet may then balance evenly upon the user's head without exertion by the user. There is also a need for a counterweight system that is adjustable for different users depending upon their physical specifications and preferences. Furthermore, it is desired that the design limit unintentional degrees of freedom of the helmet, while not restricting head movement of the user. It is to these ends that the present invention has been developed.